Pressure integrator



1965 s. E. CORRY 3,198,014

PRESSURE INTEGRATOR Filed Dec. 26, 1962 FIG.I

IIIHI H I I INVENTOR. STUART E COR RY y w w ATTORNEYS United States Patent "Ice 3,198,431.4- PRESSURE INTEGRATO Stuart E. Corry, 4605 S. Evanston, Tulsa, Okla. Filed Dec.'26,1962, Ser. No. 247,013 3 Claims. (Cl. 73-419) This invention relates to an integrating device for totaling the fluid pressure of two separate hydraulic systems.

In my Patent No. 3,060,732, issued October 30, 1962, and entitled DerrickMast With Load Checking Mechanism, I have set forth a hydraulicdevice utilized to indicate the weight on the individual legs of an oil field mast as utilized in oil well drilling and oil well servicing. Briefly stated, the device consists of two hydraulic cylinders each having a plunger therein with a mast leg set on each of the pl-ungers so that the weight on each of the mast legs is indicated by the pressure ofhydraulic fluid in one or the cylinders. Calibrated pressure gages responsive to hydraulic pressure indicates the weight on each leg of the mast. Most operators of drilling equipment need to know the total weight WhlChlS supported by the mast. Until thisinvention nolinexpensive and durable means has been known to provide accurately the total weight on the two mast legs.

The total stressa mast its associated equipment and the cables used to lower casing, tubing and so forth in and outof a well can safely tolerate has limits beyond which the operator of the drilling or service unit chances damage to his equipment. Other functions of manipulating casing, tubing andother oil field type tools-require the operator to know when changes in total supported weight have taken place; For instance, an operator frequently wants to know when casing or tubing first touches the bottom of a hole. By knowing the total weight supported by the mast the operator is able to more carefully utilize his equipment. A

It is therefore an object of device for totaling the fluid pressure of two separate hydraulic systems to produce an output fluid pressure, which output pressure is the sum of the fluid pressures of the two separate systems.

Another object .ofthis invention is to provide a device for measuring the total pressure of two separate hydraulic systemsin a manner wherein't'he fluid systems are in no way couningled. V i

Another object of this invention is to provide a simple, inexpensively constructed,sturdy and fool-proof device having a minimum number of moving parts for totaling thefluid pressure of two separate hydraulic systems.

These and other objects and a better understanding of this invention to provide a the invention may be had by refem'ingto the following description and drawings, in which:

FIGURE 1 is a diagrammatic view showingrthe integrating device of this invention in cross-section and'showing means whereby two separate hydraulic systems may .be coupled to the. device and including gages wherein pressures of the individual hydraulic systems are indicated and wherein the summated pressure of the two separate hydraulic systems is indicated.

FIGURE 2 is a cross-sectional view of the pressure integrating device taken along the line 2-2 of FIG- UREl, FIGURE 3 is a fragmentary cross-sectional view of the pressure integrating device showing an alternate embodiment modification. i 1

Briefly stated, this invention may be described as an integrating device for totaling thefluid pressure of two separate hydraulic systems. More particularly, but not by way of limitation, the invention may be described as an integrating device for totaling theflfluid pressure or two hydraulic systems, comprising, a first cylinder having a first piston therein, said first cylinder having fluid com- 3,198,914 Patented Aug. 3, 1965 munication with the first of said hydraulic systems whereby said first piston is disposed to move with a force proportional to the pressure of said first hydraulic system, a second cylinder having a second piston therein, said second cylinder having fluid communicationwith the second of said hydraulic systems whereby said second piston is disposed to move with a force proportional to the pressure of said second hydraulic system, said second system having a push rod opening therein, a push rod sealably slidably positioned in said push rod opening of said second cylinder, said push rod having engagement at one end thereof with said first piston and affixed at the other end thereof to said second piston whereby the force of movement of said first piston is exerted on said second piston, and means of detecting theforce of movement of said second piston.

Referring now to the drawings, the integrating device of this invention is indicated generally by the numeral 1th. Although the device may be of various configurations, it is preferably cylindrical wit-h three fluid openings therein designated as 12A, 12B and 12C. Fluid pressure of two separate'hydraulic systems is received in fluid openings 12A and 12B to produce a proportional total or summated fluid pressure at the outlet 12C.

Although the separate hydraulic systems producing the fluid pressure inlet communicating with openings 12A and 12B may be of any type system, a practical application of the invention, as has been previously referred to, includes the measurement of the weights exerted by the two legs of a typical drilling or work-over mast as utilized in the oil industry. Each of the legs of a mast is positioned on a hydraulic weigher 14A and 14B. Hydraulic weighers 14A and 14B may be of a variety of configurations, but consist essentially of a closed cylinder 16 in which a piston 18 is movable, A weight to be measured, such as the leg of a mast, is set on the pistons 18 so that the pressure within the bodies 20 of the hydraulic weigher 14A is proportional to the weight exerted on piston 18, indicated by the block weight number one and arrow in the drawing. The hydraulic pressure exerted by piston 18 is coupled to inlet 1 2A of the integrating device'10 through tubing22. A pressure gage 24, calibrated to reflect the weight number one, may have communication with the hydraulic weigher 14A by connection with tubing @2,

In identical manner, hydraulic weigher 14B, which may receive a weight number two, such as the second leg of an oil field mast, by means of tubing 26 applies a hydraulic fluid pressure to the integrating device 10 through opening 12B. Again, a pressure gage 28 may be calibrated to reflect the total weight applied to the piston 18. The hydraulic weighers 14A and 14B with their Weight indicator, gages 24 and 28 have been utilized very successfully in the past to indicate the weight on a mast, but no means has been provided for totaling or summating the weights so that by a single gage the total weight applied on the hydraulic weighers 14A and 14 B will be readily shown. This is accomplished by the integrating device 10. t i

As previously indicated, the integrating device 10 is shown in cross-section and consists basically of an integral cylindrical body portion 30 having a first cylinder 3 2 in one end and a second cylinder 34 in the other end. End coyer plates 36A and 36B maybe utilized to seal the cylinders 32 and 34. Fluid openings 12A and 12C are provided in the cover plates 36A and 36B. The cover plates 36A and 36B can be held in place, such as by means of bolts 38.

Slidably positioned in the first cylinder 32 is a first piston 40 which may be equipped with rings or O-ning gasket 42 to preclude the leakage of fluid past the piston. When weight number one is applied to piston 18 of hydraulic weigher 14A, fluid pressure is forced through tubing 22 to within the first cylinder 32 so that a hydraulic pressure is applied against first piston 40, moving it to the right. An air outlet opening 44 communicates the rearward end of cylinder 32 with the atmosphere so that no back pressure within cylinder 32 exerts retarding force of movement of piston 40.

A second piston 46 is sealably and slidably movable inthe second cylinder 34 and is likewise equipped with gaskets 42. Separating the cylinders 32 and 34 is a wall 48 having an opening 56 therein. Slidaibly and sealably positioned in opening 50 is a push rod 52. The opening 50 may include gaskets 54 to prevent the leakage of fluid past rod 52. 'Push rod 52 engages at one end piston 40 and is aflixed at the other end to piston 46. Push rod 52 is preferably integrally formed with piston 46,

A fluid passage 56 communicates the fluid opening 12B with the interior of cylinder 34 so that fluid pressure from hydraulic weigher 14B, by the effect of weight number two, is exerted between wall 4-8 and piston 46.

The opposite end of cylinder 34, between the piston 46 and cover plate 36B, is likewise filled with a hydraulic fluid which communicates, by way of opening 12C and tubing 58, to a pressurevg-age 60 which is calibrated to indicate weight.

The diameter-of cylinder 34 is designed such that the cross sectional area of cylinder 34 is equal to the crosssectional area of cylinder 32 plus the cross-sectional area of'rod 5 2. By this design, the total area of the end of piston 46 adjacent wall 48 less the area of rod 52 is equal to the area of the end of piston 40.

a The integrator operates as follows: When a weight number one is applied to hydraulic weigher 14A and a weight number two is applied to hydnaulic weigher 14B,

fluid pressure is exerted through tubes 22 and 26 on pistons and 46. The weight number one exerts a fluid pressure against piston 40 which forces rod 52 to the right in proportion to the amount of weight number one. This force is communicated by rod 5-2 to piston 46 which forces it to'the .rig ht wit-h an'equal force so that a pressure is applied to the fluid within cylinder 34 and thereby to gage 60 proportional to weight number one.

At the same time, weight number two applied to hydraulic weigher 14B by means of tubing 26 through openmg 12B and fluid passage 56 applies fluid pressure against the face of piston 46 forcing it to the right, which is in addition to the force applied by rod 52. Thus, a total force is applied to the hydraulic fluid within the cylinder 3-4 between piston 46 .and cover plate 36B, this total force being registered onthe pressure gage 60, which is representative of the total hydraulic pressures exerted by hydrauhc Weigher-s 14A and 1413, which in turn is proport1onal to the weights number one and number two.

"In this manner, the pressures of two separate hydraulic systems are summated to produce a total pressure at outlet 1 2C equal to the sum of the pressures applied to the device. The pressure communicated through tubing 58 may .be'measured as a total pressure, if such is desired,

or, according tothe particular application described of weighing the full weight of an oil well mast, the pressure may be calibrated in terms of weight and a total weight indicated; r

It is understood that the particular application described is strictly by way of example and that a multiplicity of applications will be suggested for determining the total pressure exerted by two independent hydraulic systems. It will also be noted that there is no comingling of the hydraulic systems and no possibility of interchange of fluid between the two.

As shown in FIGURE 2, the device is preferably cylindrical and therefore very inexpensively constructed. It is simple, straight forward and only has the two moving parts, that is, piston 40 and piston 46 with integral rod 52. Although the device is preferably cylindrical in construction it is obvious that it can take many forms. An

alternate embodiment would include constructing the cylinder 32 of two separate components and supporting them in immovable relationship with each other. All such modifications are within the purview of this invention.

The embodiment shown in FIGURE 1 produces a force of movement of piston 46 proportional to the fluid pres sure exerted in openings 12A and 128. The fluid pressure at opening 12C is proportional to the sum of these two fluid pressures but is not equal to the sum of the two fluid pressures. This is caused by the area of the piston 46 at the end adjacent opening 12C being greater than the pressure area of piston 40 and the forward pressure area (receiving pressure through opening 56) of the piston 46. The pressure at outlet 12C is proportional at all times to the sum of the pressures applied at openings 12A and 12B so that the summated pressures or weights are accurately indicated by proper calibration of gage 60.

FIGURE 3 shows an alternate embodiment of the invention wherein the pressure at outlet is equal tothe sum of the pressures into openings 12A and 12B. In

this embodiment cover plate 36B is provided with an opening which slidably and sealably receives a compensating rod 64. Rod 64 is afiixed at one end to second piston 46 and preferably is integrally formed with it. Compensating rod 64 is of the same diameter as push rod 52. Gaskets 66 may be provided at opening 62 to prevent fluid leakage; v

The provision of compensating rod 64 serves to reduce the area at the end of piston 46 adjacent opening 12C to the same area of piston 46* adjacent opening 123 and the area of first piston 40 adjacent opening 12A. In this manner the pressure at outlet 12C will equal the'sum of the pressures at openings 12A and 12B.

The integrating device 10 shown isadapted to summate the pressures of two hydraulic systems. It can be seen that by utilizing the principles of the invention an integrator can easily be constructed to summate the fluid pressures of three, four or any number of separate hydraulic systems.

Although this invention has been described with a certain degree of particularity, it is manifested that many changes may be made in the details of construction and the arrangement of components without departing from the spirit and scope of this disclosure.

What is claimed: 1

1. An integrating device for totaling the fluid pressure of two hydraulic systems, comprising:

a first cylinder having a first piston therein, said first cylinder having fluid communication with the first of said hydraulic systems wherebysaid first piston is disposed to move witha force proportional to the pressure of said first hydraulic system;

a second cylinder having a second piston therein, said second piston having fluid communication with the second of said hydraulic systems whereby said second piston is disposed to move with a force proportional to the pressure of said second hydraulic system, said second cylinder having a push rod opening therein;

a push rod sealably slidably positioned in said push rod opening in "said second cylinder, said push rod having severable contact at one end thereof with said first piston, said push rod affixed at the other end thereof to said second piston whereby the force of movement of said first piston is exerted on said second piston, the internal cross-sectional area of said second cylinder being equal to the internal crosssectional area of said first cylinder plus the crosssectional area of said rod; and

means of detecting the force of movement of said second piston.

2. An integrating device for totaling the fluid pressures of two hydraulic systems, comprising:

a tubular body member having a first closed cylinder cavity in one end thereof and a second closed cylinder cavity at the other end thereof, and a wall separating said cylinder cavities, said wall having an opening therein;

a piston slidable in said first cylinder cavity;

a piston slidable in said second cylinder cavity;

a rod extending through and sealably slidable in said opening in said Wall, said rod having severable contact at one end thereof with said piston in said first cylinder and said rod aflixed at the other end thereof with said piston in said second cylinder;

means communicating one of said hydraulic systems with said first cylinder whereby pressure of said first hydraulic system urges said piston slidable therein towards said wall and against said rod extending from said piston in said second cylinder, said first cylinder having a pressure relief opening therein adjacent said wall;

means communicating the other of said hydraulic systems with said second cylinder whereby pressure of said second hydraulic system urges said piston in said second cylinder away from said wall, said second cylinder having a pressure outlet opening therein adjacent the end thereof opposite said wall, said second cylinder and said pressure outlet opening having hydraulic fluid therein, the internal cross-sectional area of said second cylinder being equal to the internal cross-sectional area of said first cylinder plus the cross-sectional area of said rod, the pressure of said hydraulic fluid at said pressure outlet representing the sum of the pressures of said two hydraulic systems.

3. An integrating device for totaling the fluid pressures of two hydraulic systems, comprising:

a tubular body member having a first closed cylinder cavity in one end thereof and a second closed cylinder cavity in the other end thereof, a wall separating said cylinder cavities, said wall having an opening therein and wherein the said closed second cylinder has an opening therein opposite said opening in said wall;

a first piston slidable in said first cylinder cavity;

RICHARD C. QUEISSER, Primary Examiner.

a second piston slidable in said second cylinder cavity,

means communicating one of said hydraulic systems with said first cylinder whereby pressure of said first hydraulic system urges said first piston slidable therein towards said Wall and against said push rod extending from said piston in said second cylinder, said first cylinder having a pressure relief opening therein adjacent said wall;

means communicating the other of said hydraulic systems with said second cylinder whereby pressure of said second hydraulic system urges said piston in said second cylinder away from said wall, said second cylinder having a pressure outlet opening therein adjacent the end thereof opposite said wall, said second cylinder and said pressure outlet opening having hydraulic fluid therein, the internal crosssectional area of said second cylinder being equal to the internal cross-sectional area of said first cylinder plus the cross-sectional area of said push rod and the cross-sectional area of said push rod being the same as the cross-sectional area of said compensating rod, the pressure of said hydraulic fluid at said pressure outlet representing the sum of the pressures of said two hydraulic systems.

References Cited by the Examiner UNITED STATES PATENTS 5/62 Brown 73--407 JOSEPHP. STRIZAK, Examiner. 

1. AN INTEGRATING DEVICE FOR TOTALING THE FLUID PRESSURE OF TWO HYDRAYLIC SYSTEMS, COMPRISING: A FIRST CYLINDER HAVING A FIRST PISTON THEREIN, SAID FIRST CYLINDER HAVING FLUID COMMUNICATION WITH THE FIRST OF SAID HYDRAULIC SYSTEMS WHEREBY SAID FIRST PISTON IS DISPOSED TO MOVE WITH A FORCE PROPORTIONAL TO THE PRESSURE OF SAID FIRST HYDRAULIC SYSTEM; A SECOND CYLINDER HAVING A SECOND PISTON THEREIN, SAID SECOND PISTON HAVING FLUID COMMUNICATION WITH THE SECOND OF SAID HYDRAULIC SYSTEMS WHEREBY SAID SECOND PISTON IS DISPOSED TO MOVE WITH A FORCE PROPORTIONAL TO THE PRESSURE OF SAID SECOND HYDRAULIC SYSTEM, SAID SECOND CYLINDER HAVING A PUSH ROD OPENING THEREIN; A PUSH ROD SEALABLY SLIDABLY POSITIONED IN SAID PUSH ROD OPENING IN SAID SECOND CYLINDER, SAID PUSH ROD HAVING SEVERABLE CONTACT AT ONE END THEREOF WITH SAID FIRST PISTON, SAID PUSH ROD AFFIXED AT THE OTHER END THEREOF TO SAID SECOND PISTON WHEREBY THE FORCE OF MOVEMENT OF SAID FIRST PISTON IS EXERTED ON SAID SECOND PISTON, THE INTERNAL CROSS-SECTIONAL AREA OF SAID SECOND CYLINDER BEING EQUAL TO THE INTERNAL CROSSSECTIONAL AREA OF SAID FIRST CYLINDER PLUS THE CROSSSECTIONAL AREA OF SAID ROD; AND MEANS FOR DETECTING THE FORCE OF MOVEMENT OF SAID SECOND PISTON. 